Funds are requested to initiate a long-term program of research on learning in reproductive behavior systems, as a way to continue the study of adaptive specializations and biological constraints on learning. Adaptive specializations are expected to be found in sexual learning because reproductive behavior is shaped directly by natural selection and occurs in diverse forms in different species. We will seek to discover whether species differences in reproductive behavior are accompanied by differences in sexual learning and relate these findings to the mating system of each species. Experimentation will begin with Japanese quail, which are promiscuous in captivity and can be raised without parental involvement. during initial studies, we will document classical conditioning of sexual arkusal in male birds in response to visual and auditory cues signalling the presentation of a receptive female. We will then investigate how the learning is influenced by the interval between presentation of a signal and subsequent sexual opportunity, and the nature of the sexual encounter. The research is expected to advance knowledge about learning mechanisms, sexual behavior, and the integration of studies of animal learning with biological concerns about behavior. As the research progresses, it may have implications for the treatment of human sexual disfunction since human sexual arousal is strongly influenced by learning.